Avionic tray

ABSTRACT

An avionic tray is disclosed having a backplate secured between a pair of vertical uprights of the tray with the aid of selfjigging structure located thereon. The vertical uprights include a plurality of jig pins formed on the interior sides thereof which are adapted to snap into a plurality of registering holes formed in the backplate. The jig pins are formed by a half-shear punch process, while the holes are also formed by a punching process. A pair of precision dies are used to accurately locate the jig pins and holes to ensure precise linear and angular positioning of the backplate relative to the tray prior to securing the backplate to the uprights with rivets, bolts or other attachment means.

United States Patent 1 Hollingsead et al.

[54] AVIONIC TRAY -[75] lnventors: Robert A. Hollingsead, Yorba Linda;Clyde Robert Pryor, Anaheim, both of Calif.

[73] Assignee: Hollingsead-Pryor Enterprises, Inc.,

Santa Fe Springs, Los Angeles.

County, Calif.

[22] Filed: March 18, 1971 [21] Appl. N0.: 125,536

3,426,419 2/1969 Banks ..29/200 P [451 Jan. 16, 1973 PrimaryExaminer-Thomas H. Eager Attorney.lackson & Jones [57] ABSTRACT Anavionic tray is disclosed having a backplate secured between a pair ofvertical uprights of the tray with the aid of self-jigging structurelocated thereon. The vertical uprights include a plurality of jig pinsformed on the interior sides thereof which are adapted to snap into aplurality of registering holes formed in the backplate. The jig pins areformed by a half-shear punch process, while the holes are also formed bya punching process. A pair of precision dies are used to accuratelylocate the jig pins and holes to ensure precise linear and angularpositioning of the backplate relative to the tray prior to securing thebackplate to the uprights with rivets, bolts or other attachment 10Claims, 5 Drawing Figures AVIONIC TRAY BACKGROUND OF THE INVENTION 1.Field of the Invention v The present invention relates to means forattaching one member to another and more particularly to means foraccurately positioning the two members prior to securing the two memberstogether.

2. Description of the Prior Art In an aircraft, each piece of electronicequipment is supported on an individual tray. Each tray usuallycomprises a bottom section having a pair of side rails extendingupwardly therefrom. The side rails function as guides for the supportedinstrument during installation and also serve as a lateral support afterinstallation. The side rails further include a pair of upright sectionswhich are adapted to be connected to and support a backplatetherebetween.

The backplate usually includes a pair of dagger pins accuratelypositioned on its front face for mating with the rear of the instrumentto function as a rear hold down. An electrical receptacle is mounted onthe backplate and functions to receive the connectors extending out ofthe rear end of the instrument. The backplate is also provided with acut-out portion for receiving a portion of the receptacle along with thereceptacle wires. After the backplate is connected to the tray, thebackplate functions to absorb a hold-down load that is applied to theinstrument from the front of the shelf. This hold-down load, usually ofthe magnitude of one hundred pounds, is necessary to secure theinstrument during flight.

A serious shortcoming involved with prior assemblies is that because ofthe tolerance buildup involved in connecting the backplate to the tray,a great amount of misalignment occurs. This not only results in theimproper support of the instrument but also results in faulty electricalconnections between the instrument and the receptacles. This tolerancebuildup occurs in the bolting or riveting process used ininterconnecting the backplate to the upright sections of the tray. Morespecifically, in drilling the bolt or rivet holes in the two elements,care must be taken to ensure that the center lines of the holes in eachside of the connections are perpendicular to the bottom section of thetray. If such drilling is done by hand, inaccuracies occur that arequite large. If the drilling is done by machine, the accuracy isimproved.

However, even if the center lines are perfect, there is a toleranceproblem in forming the holes to accept the rivets or bolts. This isbecause inthe manufacturing of rivets or bolts, there is an acceptabletolerance in which the bolt or rivet diameter can be manufactured. As aresult, the holes must be drilled to such a size that even the largestbolt made within those tolerances can go through. Moreover, the holesare made within tolerances also. As a result, the holes must bedimensioned such that the low side of the tolerance level of the holesbe sufficient to accommodate the bolts made on the high side of itstolerance level.

It follows, then, that through random selection, a small bolt can bemounted in relatively large holes in the backplate and uprights.

Upon installing the backplate, the bolts are inserted in upper and lowerregistering holes of the side sections of the backplate and theuprights. Because of the loose fit of the bolts, the backplate can beeasily tilted as the bolts are applied. In fact, the bottom of thebackplate can move in one direction the total amount of tolerances foundin the two holes and the bolt, while the upper portion of the backplatecan move the same distance in the opposite direction. This tolerancebuildup can actually result in a total angular displacement of up to 15from the perpendicular. Not only is this angular displacement of thebackplate sufficient to cause misalignment of the instrument, but it issufficient enough to prevent the instrument from being properlyconnected to the electrical receptacle mounted on the backplate.

SUMMARY OF THE INVENTION The present invention obviates theabove-mentioned shortcoming by providing self-jigging means forperpendicularly mounting the backplate on the tray with a high degree ofaccuracy.

In accordance with the present invention, the uprights of the tray areprovided with jig pins formed thereon which are adapted to mate withregistering apertures on the backplate to permit the backplate to besnapped onto the uprights in a perpendicular relationship before thebolts or rivets are secured within the holes.

In forming these jig pins on the uprights, a die having a perpendicularedge is positioned adjacent the bottom surface of the tray. A pair offemale holes is located on each side of the die with the center lines ofthese holes being perpendicular to the base plate. A pair of malepunches of a diameter larger than the diameter of the female holes isthen applied to the opposite side of the uprights to press metal fromthe uprights inwardly into the female holes of the die. The punchesextend half way into the uprights to half-shear the pressed metal toform. a plurality of jig pins. Registering holes are likewise formed inthe backplate with the exception that punches equal to the size of thefemale holes are utilized to extend entirely through the material of thebackplate and completely shear off the metal and form the holes.

- The main advantage of the present invention is that theinterconnecting members have self jigging means formed thereon whichfunction to align the backplate in a perpendicular position with respectto the tray with a high degree of accuracy prior to applying the boltsor rivets. In this manner, the interconnection of the memhers is notinfluenced in any way by the tolerance buildup or the rivet or boltmeans.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. The presentinvention, both as to its organization and manner of operation, togetherwith further objects and advantages thereof, may best be understood byreference to the following description, taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of anavionic die apparatus having a backplate positioned between two uprightsby means of self-jigging means in accordance with the present invention;

FIG. 2 is a fragmentary perspective view showing a die positioned on thetray to form the jig pins;

FIG. 3 is a fragmentary perspective view of the rear of the backplate,showing a die positioned therein to form the jig holes;

FIG. 4 is an enlarged fragmentary sectional view of the jig pinconnection; and 7 FIG. is a fragmentary perspective view of theapparatus in its assembled form.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,FIG. 1 shows an avionic tray, generally indicated by arrow 10, forsupporting an electronic instrument (shown in broken lines). The tray 10comprises a bottom section 11 and a pair of side rails 13 extendingupwardly along the lateral edges thereof. The bottom section llisadapted to be mounted'at its ends to a pair of cross channels 15. Thebottom section 1 1 also includes a metering section 17 extending belowthe surface of the tray with-the metering section 17 having a pluralityof metering ports 19 for controlling the amount of air drawn through theinstrument.

An annular'gaske t 21 extends around the periphery of the meteringsection 17 and above the surface of the tray to sealingly engage thebottom of the supported instrument.

The side rails 13 further include a pair of uprights 23 which areadapted to be connected to and laterally support a backplate 25.Thebackplate 25is perpendicularly positioned with respect to the bottomsurface of the tray and includes a pair of dagger pins 27 for matingwith a pair of registering apertures on the supported instrument. Thebackplate further includes a cut-out portion 29 for receiving a portionof an electrical receptacle (not, shown) along with the receptaclewires. The backplate 25 functions to support the rear of the instrumentas a holding force is applied at the front of the instrument. Moreover,the perpendicular orientation of the backplate 25 permits the instrumentto lie flush against the backplate 25 to ensure a proper electricalconnection between the instrument and the receptacle.

The backplate 25 is secured to the uprights 23 by means of bolts 31extending through registering holes 33 formed on the uprights 23 and thelateral sides 35 of the backplate 25 Prior to such connections, however,the backplate is mounted on the uprights by means of jig pins 37 formedon the interior sides of the uprights 23 which extend into a pluralityof registering apertures 39 formed in the lateral sides 35 of thebackplate 25.

As shown in FIG. 2, in fabricating the jig pins 37, a die 41 is utilizedhaving a face portion 43 on the bottom edge thereof which is adapted tocontact the bottom surface of the tray 10. A plurality of femaleapertures 45 is formed within the lateral sides of the die 41 with eachpair of apertures being accurately formed to cause their center lines tobe perpendicular to the face portion 43.

In operation, the die 41 is mounted on the tray 10 in such a manner thatthe face portion 43 rests against the bottom section 11 of the tray 10and the female apertures 45 are aligned adjacent the uprights 23. Aplurality of punches 47 are then provided to contact that por-, tion ofthe uprights 23 that registers with the female apertures 45. The punches47 are dimensioned to be larger than the diameter of the femaleapertures. In

pressing the material with the punches 47 a portion of the uprightmaterial is forced into the female apertures 7 ensured. The punchestravel about half way through the uprights to create the half-shearedpins 37.

As shown in FIG. 3, a second die 49'is provided to extend within thecavity formedin the backplate 25. The die 49 includes a face portion 51adapted to lie flush against the rear surface of the backplate 25 and apair of lateral sides having pairs of female apertures 53 whose centerlines are parallel to the face portion 51.

A second plurality of punches 55 are provided to contact the backplatematerial adjacent the female apertures 53 with the punches being of thesame cross sectional area as the female apertures. This permits thepunches 55 to extend entirely through the backplate material tocompletely shear off the punched out portion to form the apertures 53.

In connecting the backplate 25 to the tray 10, the

backplate 25 is first snapped onto the jig pins 37 of the uprights 23. Atypical connection is shown in FIG. 4. Because of the exceptionally lowtolerances of i the manufacturing process, the backplate isprecisionally positioned to be perpendicular with respect to bottomsection 11 of the tray 10. In such a secured position the bolts 31 arethen inserted through the aligned holes 33 with each connection beingsecured by a nut. The backplate 25 is shown connected to the uprights 23in FIG. 5.

As can be seen, the backplate 25 is secured in position before the bolts31 are used. As a result, the positioning of the backplate 25 iscompletely independent of the tolerance buildup found and the holes.

Moreover, the forming of the jig pins 37 and apertures 39 isaccomplished with a very high degree of accuracy. The dies 41 and 49 areboth precisionally made and are easy to operate.

It should be noted that various modifications can be made to theapparatus while still remaining within the purview of the followingclaims.

It should also be noted that such self-jigging means can be used tosecure any two elements together whenever precision alignment isrequired.

What is claimed is:

1. Apparatus for securing a backplate member 'on a tray comprising: I

a pair of vertical upright members connected to said tray, saidbackplate member positioned between said upright members;

a plurality of jig pins aligning said upright members .and saidbackplate member and formed on .at least one of said members; and

a plurality of jig holes formed on the other of said members forregistering with said jig pins.

2. The apparatus of claim 1 further comprising means for securing saidvertical upright members to said backplate member after said jig pinsare engaged in said jig holes.

3. The apparatus of claim 1 wherein said jig pins are integrally formedfrom the material of one of said members.

in the use of the bolts pendicular to the surface of said tray.

5. The apparatus of claim 1 wherein said tray is an avionic tray adaptedto support electronic equipment and said backplate is adapted to matewith said electronic equipment for fastening said electronic equipmentin position and said vertical uprights are integral with said avionictray.

6. The apparatus of claim 1 wherein said tray is an avionic tray adaptedto support electronic equipment and said backplate is adapted to matewith said electronic equipment for fastening said electronic equipmentin position; a metering plate for controlling air flow to saidelectronic equipment and a gasket for sealingly engaging said electronicequipment, said evionic tray having an opening on its surface forreceiving said gasket and metering plate.

7. The apparatus of claim 2 wherein said means for securing includessaid members having holes extending therethrough and fasteners forinterconnecting said members.

8. The apparatus of claim 5 wherein a pair of jig pins are provided oneach side of said tray.

9. The apparatus of claim 8 wherein means for locking said verticalmembers are provided between said jig pins.

10. The apparatus of claim 8 wherein said jig pins are I integrallyformed of the material of one of said members.

1. Apparatus for securing a backplate member on a tray comprising: apair of vertical upright members connected to said tray, said backplatemember positioned between said upright members; a plurality of jig pinsaligning said upright members and said backplate member and formed on atleast one of said members; and a plurality of jig holes formed on theother of said members for registering with said jig pins.
 2. Theapparatus of claim 1 further comprising means for securing said verticalupright members to said backplate member after said jig pins are engagedin said jig holes.
 3. The apparatus of claim 1 wherein said jig pins areintegrally formed from the material of one of said members.
 4. Theapparatus of claim 1 wherein said jig pins are formed such that thefront face of the backplate is perpendicular to the surface of saidtray.
 5. The apparatus of claim 1 wherein said tray is an avionic trayadapted to support electronic equipment and said backplate is adapted tomate with said electronic equipment for fastening said electronicequipment in position and said vertical uprights are integral with saidavionic tray.
 6. The apparatus of claim 1 wherein said tray is anavionic tray adapted to support electronic equipment and said backplateis adapted to mate with said electronic equipment for fastening saidelectronic equipment in position; a metering plate for controlling airflow to said electronic equipment and a gasket for sealingly engagingsaid electronic equipment, said evionic tray having an opening on itssurface for receiving said gasket and metering plate.
 7. The apparatusof claim 2 wherein said means for securing includes said members havingholes extending therethrough and fasteners for interconnecting saidmembers.
 8. The apparatus of claim 5 wherein a pair of jig pins areprovided on each side of said tray.
 9. The apparatus of claim 8 whereinmeans for locking said vertical members are provided between said jigpins.
 10. The apparatus of claim 8 wherein said jig pins are integrallyformed of the material of one of said members.